Freescale Semiconductor, Inc.
EPROM/ OTPROM
13.3.3 EPROM Se c urity Bit (EPMSEC)
An EPROM programmable bit is provided at the location of the COP
watchdog register at $1FF0 as shown in Figure 13-3. This bit allows
control of access to the EPROM array. Any accesses of the EPROM
locations will return undefined results when the EPMSEC bit is set. Refer
to 13.4.2 EPMSEC Programming for programming instructions.
$1FF0
Read:
Bit 7
6
5
4
3
2
1
Bit 0
COPC
—
EPMSEC
OPT
Write:
Reset:
Erased:
Unaffected by Reset
0
—
—
—
—
—
—
= Unimplemented
Figure 13-3. EPROM Security in COP Register (COP)
1
EPMSEC — EPROM Security
This EPROM write-only bit enables the access to the EPROM array.
1 = Access to the EPROM array in non-user modes is denied
0 = Access to the EPROM array in non-user modes is enabled
13.4 EPROM Prog ra m m ing
A programming board is available from Motorola to download to the on-
chip EPROM/OTPROM using the factory-provided programming
software. Factory-provided software for programming the EPROM is
available through the Motorola Freeware Bulletin Board Service (BBS).
The number is (512) 891-FREE. After making the connection, type bbs
in lowercase letters and press the return key to start the BBS software.
The programming software copies to the 6144-byte space located at
EPROM addresses $0700–$1EFF and to the 16-byte space at
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or
copying the EPROM/OTPROM difficult for unauthorized users.
General Release Specification
MC68HC705JJ7/MC68HC705JP7 — Rev. 3.0
EPROM/OTPROM
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